Cubase 12 slowing down/Peak Meter going crazy

Hello everyone,

maybe someon can help me in here.
Lately I bought the Spitfire Audio BBC SO Core.
Since then something broke my cubase and I don’t know if that’s related, but buying the Spitfire thing and the start of those problems are correlating.
When I hit play (it does not matter if there are instruments loaded, audio channels with events on it or nothing at all) cubase starts to get slow. As soon as for example move the scrollbar on the mixer I get frame skipping in all windows. That does not affect the audio. But when I use a vst instrument like Random where you can sort of scrub the squishy black thing in the middle of the screen to modulate the sound, you can hear a lot of crackles (latency) and also see frame skipping. This of course is happening during playback. Meanwhile the Real-Time and Peak-Meter are going crazy, even if there is nothing loaded in the project except for said instrument. This also happens with other instruments.
Now I’ve read about a bug with the ASIO-Guard, where you should delete the current and create a new output and save. But that did not help at all.
CPU-Usage is normal at around 10% or something and during playback I can work just fine with other programs on my pc next to cubase still playing.
Opening and Closing Projects is awfully slow as well.
Changing the Buffersize of my scarlett 18i20 3rd gen did make no difference.
I have a AMD Ryzen 5 3600X 6-Core Processor (3.79 GHz). I am running
I am running Cubase 12 Pro Version 12.0.52. Build 393.
Since nothing helped, can someone help with this?

Thanks in advance


Try to test your system by using LatencyMon utility, please.

Increasing the Buffer Size should help.

I believe, there are also tutorials, how to optimise Kontakt settings.

Download the latest updates of the plug-in and also Cubase (12.0.70), please.

Hey Martin,

LatencyMon said that everything should be just fine (everything lit up green).
Changing the Buffer Size did not change anything for me.
The Spitifre BBC SO is not used with Kontakt but their own plugin which is the latest version. And as stated this also happens, when I have an empty project (no instruments or plugins loaded, just 40 audio tracks with no events on them for example).
Is there any possibility to update cubase without the download assistant? Because I had to install cubase without it as the download assistant is still not working (cannot connect to the download server) and i cannot find any solution for that? Re-Installing Cubase completely?


Make sure Steinberg Download Assistant is up to date, please.


can’t get it to work.
Downloaded the latest version.
But it still can’t connect to the server, even with firewall and anti-virus off.
So, I need to solve this issue first, before being able to update cubase…

So, I couldn’t get it to update and i had to reinstall cubase manually, which is a real drag, but it seems to have resolved the issue of lagging and meter-peaking for now.
Let’s hope it will stay this way…
Thanks for your help.